Tank



F. S. BOLTZ March 24, 1931.

TANK

Filed Jan. 20, 1928 inventor.- 5 844 0. 5+ y mpw .CWMLQ Patented Mar. 241931 UNITED STATES FRED S. BOLTZ, OI MANSFIELD, MASSACHUSETTS TANKApplication filed January 20, 1928. Serial No. 248,146.

The invention relates to an improvement in tanks. It is especiallyintended for application to tanks which are intended for use ascontainers for hot water or other liquids or substances which have atendency to corrode metal. When the tank is made entirely of sheet steelor other corrodible metal, it soon becomes corroded thereby causing thetank to leak and discoloring the liquid in the tank.

The use of non-corrodible metal for the entire tank is very expensive ifthe sheets of which the tank is made are sufiiciently thick to give thenecessary strength. It has, therefore, become common to make the tankwith an inner shell or lining of non-corrodible metal and with an outeror reenforcing shell of steel or other relatively cheap metal-which iscorrodible.

One object of the present invention 1s to provide a form of joints whichwill be noncorrodible and is easily made.

Another object of the'invention is to provide an interlocking joint forthe meeting edges of the sheets which form the body of the container.

Another feature is to provide a special reenforcing strip on the outsideof the tank to cover the side joint.

The invention will be fully understood I from the following descriptionwhen taken in connection with the accompanying drawings and the novelfeatures thereof will be pointed out and clearly defined in the claimsat the close of this specification.

Fig. 1 is a longitudinal section of a tank embodying the invention.

Fig. 2 is a section on line 2-2, Fig. 1.

Fi 3 is an enlarged detail sectional view showmg the reenforcing stripin combination with the inner and outer shell.

Referring to the drawings, there is shown at 1.0 a tubular outer orreenforcing shell of the tank which may be made of steel or other withtwo heads B, C, preferably dished inward to enable workmen to make atight joint easily from outside of the tank. At D is shown a heatingelementjconnected with the head C in any suitable manner. Any suitableheating element may be used for this purpose as this forms no part ofthe invention. The longitudinal side edges of the inner shell 11 ofnon-corrodible metal abut each other and are formed with outwardlyturned lips or flanges 16 which preferably flare somewhat away from eachother as shown in Fig. 3, leaving a V-shaped notch between them. Theside edges 17 of the outer or reenforcing shell 10 are beveled as shownin Fig. 3 and flare away from each other. The inner corners 9 of saidreenforcing shell engage the said flange 16, 16 of the lining shell.There is thus formed a sort of wedge-shaped or inwardly tapering recessbetween the adjacent edges of said outer shell and a V-shaped notchbetween the flanges 16,16 of the inner shell. The adjacent edges of thereenforcing shell and of the non-corrodible inner shell are all unitedtogether as shown at 18 by welding or brazing or other non-corrodiblematerial adapted to fill the said recess between the adjacent ends ofthe outer shell and of the V-shaped recess between the'two flanges 16,16 of the inner shell and unite the parts together. The filling isflaring sided in cross section as shown in Fig. 3, the broad side orhead of the wedge being on the outer side. In order to further protectthe joint against fracture there is provided a longitudinal coveringstrip 19 which may be of steel or other suitable metal which covers theouter face of the block of filling 18 and this strip overlaps theadjacent sidesof the outer metal shell 10 far enough to cover the entirejoint. This strip is secured to the outer face of the shell 10 by anysuitable means, preferably by welding or soldering as shown atcbrrodible sheet metal and at 11 is shown an 20 4 inner shell ofnon-corrodible sheet metal, preferably brass, copper or Monel. Each ofthese shells is made 0 sheet metal rolled into cylindrical form andhaving a longitudinal union or joint at the meeting edges. The

60 ends of the tank are provided respectively What I claim is:

1. A sheet metal tank comprisin an inner tubular shell formed of a sheet0 non-corrodible metal and a reenforcing outer metal shell, the adjacentside edges of the sheet forming the inner shell having flanges whose 0adjacent faces flare away from each other, the ad acent side edges ofsaid outer shell engaging said flanges of the inner shell and arin awayfrom each other, thereby formin a flaring-sided groove between the edgessaid outer shell, and said groove having a filling of solder or the likewhich unites together said outer shell and inner shell by a water tightjoint and a covering strip which extends engthwise of the shell andcovers the said filling and laps over onto the periphery of the outershell.

2. A tank comprisin an outer shell consisting of sheet metal ormed intoa tube, a lining shell of non corrodible sheet metal, the adjacent edgesof the outer shell being spaced apart from each other, the adjacentedges of t e lining shell being formed with flanges which extend intothe space between the edges of the outer shelland a uniting substance inthe space between the edges of the outer shell whic unites the twoshells together along the said adjacent edges.

' ing sided groove,

3. A tank comprising an outer shell consisting of a sheet of metalshaped to substantially tubular form with a space between the adjacentlongitudinal ed es of the. sheet, a linin shell 0 sheet meta formed intoa tube w ose ad'acent longitudinal edges are formed with anges whichroject into. the space between the adjacent edges of the outer shell anda uniting substance in the space between the edges of the outer shellwhich unites the two ells together along the said adjacent edges. 4. Atank comprising an outer shell consisting of a sheet of metal formedinto a tube with a longitudinal o ni'ng between the adjacentlongitudinal ges of the sheet, a linmdg shell of metal formed into atube whose a acent lon 'tudinal edges are formed with flanges whicproject into the space between the ad'acent e ges of the outer shell, auniting su stance in the space between the edges of said shells whichunites the two shells together along the said adjacent edges, and acovering strlp which extends len hwise of the outer shell and covers thesa1d unitin substance and laps over onto the periphery 0 said outershell.

5. A tank comprising an outer shell consisting of a sheet of metalshaped to substantiall tubular form with a longitudinal o ning tween theadjacent edges of the s eet and a lining shell of sheet metal formedinto a tube whose adjacent edges are formed with flanges which projectinto the space between the adjacent edges of the outer shell, theadjacent faces of the flanges of said inner shell flaring away from eachother forming a flarsaid groove having a filling zfibisltance whichunites together said outer 6. A tank havin a body portion comprising twometallic Smalls, one forming a lin-

